1. Field of the Invention
This invention relates to a solar cover for a motor vehicle roof with a carrier plate, a plurality of solar cells located on the carrier plate, and a cover which covers the side of the solar cells facing away from the carrier plate.
2. Description of Related Art
A solar cover of the above-mentioned type is known from published German Patent Application DE 198 13 324 A1 and corresponding U.S. Pat. No. 6,155,635, which describe a frameless solar cover in which between an essentially flat outside cover plate and an inside cover there is plurality of solar cells. In the installation of the solar cover, a soft embedding material is applied to the cover plate and the solar cells are inserted into it, the embedded solar cells finally being covered by a cover, for example, a film or a thin plate. Production of this solar cover is problematical in that the solar cells must be positioned very precisely on the cover plate before lamination or sealing; this is rather difficult on the flat cover plate.
Furthermore, published German Patent Application DE 38 35 560 A1 describes a plastic roof for motor vehicles which has a profile frame which is made to accommodate the outside roof shell and the inside roof lining, with reinforcements in the form of a lattice or honeycomb structure. According to one preferred embodiment, in the honeycomb, there can also be stiffening surfaces on which the solar cells can be located. The roof described in published German Patent Application DE 38 35 560 A1 is disadvantageous in several respects. On the one hand, the cross section in the proposed structure is rather tall and is therefore not suitable for movable cover elements. On the other hand, as a result of the lattice element, transparent or partially transparent roof elements cannot be made since the lattice element must be covered with an opaque cover. In addition, it is extremely difficult to wire the solar cells which are located in the cells of the lattice structure since the solar cells must make contact with the openings provided in the stiffening surfaces from underneath; however, the respective contacts then emerge in the honeycomb structure which hinders the connection of the individual contacts.
German Patent DE 197 16 389 A1 discloses a plastic cover which has a trough-shaped receiver for the solar cell assembly on its bottom. On the side edges, there are projections which, on the one hand, facilitate the positioning of the solar cells, and on the other, are used as a support for a glass plate as a cover on the inside.
Thus, a primary object of this invention is to devise a solar cover of the initially mentioned type which can be produced and installed more easily.
In accordance with the invention, this object is achieved by a plastic injection molding being used as the carrier plate in which contours are molded for positioning of the solar cells. Because the solar cover for a motor vehicle roof is provided with a plastic injection molding as the carrier plate in which contours are molded for positioning of the solar cells, the positioning of the solar cells is greatly facilitated in installation. Preferably, the contours are chosen such that the position of each individual solar cell is stipulated. However, embodiments are advantageous relative to the prior art in which the contours determine the position of only individual rows or groups of solar cells, but not the position of each cell within the row or group, as was explained with reference to published German Patent Application DE 198 13 324 A1. The cover according to the invention has a simple structure comprised of few parts and can still be produced quickly and economically.
In particular, for purposes of forming the contour, the carrier plate can be provided with depressions and/or can have connectors, the size of the depressions or the distance of the connectors preferably corresponding to the size of the solar cells. In this way, definite and exact positioning of the solar cells is achieved which does not allow the solar cells to be off-center relative to one another during lamination or sealing. Thus, the installation cost and the time necessary for production of the solar cover can be greatly reduced, and at the same time, the fault rate or scrap rate is reduced since a critical source of faults, i.e., off-center solar cells, can be completely precluded.
In another embodiment of the invention, the contours can comprise positioning aids for positioning of the printed conductors used for making contact with the solar cells. These contours can be produced, for example, by there being openings in the connectors between the individual solar cells into which the printed conductors are inserted. In addition, the contours can also have means for locking of the solar cells and the printed conductors, for example, catch hooks, projections, projecting edges and the like.
Conventionally, the solar cells can be embedded in a hot melt adhesive film, for example consisting of ethylene vinyl acetate, or a sealing compound. To position the hot melt adhesive films it is advantageous if the carrier plate on its inside has fixing elements for the hot melt adhesive films. They can be made, for example, as domes on the four corners of the trough-shaped depression of the carrier plate.
Since both the carrier plate and also the outside pane should be made as a more stable element, to achieve an especially light cover which is composed of few parts, it is especially advantageous if the functions of the outside pane and those of the carrier plate are combined in one component. According to one especially preferred embodiment of the invention, therefore, the carrier plate is produced from transparent plastic and is used as the outside pane of the solar cover, with the solar cells attached to its underside. If a solar cover is to be built which is formed of as few parts as possible, and which can therefore be installed especially quickly and easily, the carrier plate can also be made such that it comprises further components as can be conventionally found in solar covers, especially a reinforcing frame, fastening elements for connection to the fixed motor vehicle roof, fastening elements for connection to the roof mechanism for moving the cover element, and the like. These components can be made in one piece during the production of the carrier element at the same time or can be cast onto the pre-cast carrier element.
If the line arrangements which are intended for connecting the solar cells to the motor vehicle electrical system are to be protected from viewing from the outside, in the edge area of the transparent carrier plate in which there are the indicated line arrangements, there can be a nontransparent material. Here, it can be a colored layer which is applied to the edge area before the line arrangements are attached, or there can be a component of opaque material which bears the line arrangements. In particular, the component of opaque material can be a plastic injection molded part which is injected onto the transparent carrier plate. The opaque material can be the same material as that of the transparent carrier plate, in this case the material being dyed in order to prevent it from being looked through.
To protect the top of the transparent cover plate against damage, especially against UV effects or scratching, it can be coated with a transparent protective varnish. Especially advantageous coatings can be polysiloxane varnishes, xe2x80x9cOrcomersxe2x80x9d or nanometer coatings.
One preferred embodiment of this invention is explained in detail below with reference to the accompanying drawings.